Systems employing a symmetric encryption method require that the sender and receiver of a cipher text message have the same encryption and decryption key. Providing the key to the receiver poses a risk in that if the key is compromised, by a nefarious third party, then all subsequent cipher text will be compromised, until the key is updated. For this reason, key protection and management is a critical part of systems employing crypto equipment. Proposed in this application is a novel method for key distribution.
There are a number of ways that keys are presently distributed. All methods require a coordinated key exchange. These methods are a function of the type of mission and type of encryption. In symmetric key cryptography, both parties must possess a common key. Distribution of keys is done according to an approved security plan. Methods of exchanging keys include first person exchange, by couriers with secure pouches, or sending the key through an existing encryption channel. The problem with the above method is that if the key becomes compromised, then all subsequent messages are compromised until the key is updated.
In view of the above discussion, it would be beneficial to have secure means for distributing encryption or decryption keys. It would be further beneficial to have a method of key distribution that does not require users on either end of the data link to handle the keys or to have prior knowledge of the keys. It would be further beneficial to have a method of key distribution where the keys are not persistent and can be rotated as frequently as desired, and even support multiple encryption keys per message.